Linked Life Data

11792733

Source:http://linkedlifedata.com/resource/pubmed/id/11792733

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2002-1-16
pubmed:abstractText
In this study, the substrate specificity of a newly identified rat brain ceramidase (CDase) was investigated. To this end, the major functional groups and stereochemistry of ceramide (Cer) were evaluated for their influence on the hydrolysis of substrate by this CDase. The results showed that, of the four possible stereoisomers of Cer, only the natural d-e-C(18)-Cer isomer was used as substrate (K(m) of 1.1 mol% and V(max) of 5 micromol/min/mg). Removal of the 4-5 trans double bond to generate dihydroceramide decreased the affinity of the enzyme toward its substrate by around 90%, whereas changing the configuration of the double bond from the natural trans configuration into cis or introduction of a hydroxyl group (phytoceramide) resulted in loss of hydrolysis. Shortening the chain length of the sphingosine backbone resulted in decreased affinity. Methylation of either the primary or the secondary hydroxyl groups resulted in loss of activity. Results also indicated that Cer species that harbor long saturated or monounsaturated fatty acyl chains are preferred substrates of the enzyme. alpha-Hydroxylated Cer demonstrated considerably higher affinity, indicating a preference of the enzyme to those Cer molecular species. These results disclose a very high specificity of nonlysosomal CDase for its substrate, Cer.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0022-2275
pubmed:author
pubmed:issnType
Print
pubmed:volume
43
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
141-8
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Substrate specificity of rat brain ceramidase.
pubmed:affiliation
Department of Biochemistry and Molecular Biology, Medical University of South Carolina, 171 Ashley Avenue, Charleston, SC 29425, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.